Problem: $\dfrac{9}{12} + \dfrac{7}{2} = {?}$
Solution: $ = {\dfrac{9 \times 1}{12 \times 1}} + {\dfrac{7 \times 6}{2 \times 6}} $ $ = {\dfrac{9}{12}} + {\dfrac{42}{12}} $ $ = \dfrac{{9} + {42}}{12} $ $ = \dfrac{51}{12}$